LAUSR

We read with interest the study done by Rossi et al. recently published in Intensive Care Medicine [1]. In this study, the authors have studied the anatomical and physiological bases of oxygenation response to proning and recruitment maneuvers (RM) in acute respiratory distress syndrome (ARDS), by assessing gas exchange, lung mechanics, computed tomography (CT) chest scans and hemodynamics in coronavirus 2019 disease (COVID-19) patients with varied time period (3–24 days after hospital admission) [1]. Their findings are suggestive of lesser benefit of recruitment on oxygenation by the third week of illness in COVID ARDS. Moreover, they have been dil-igent enough to calculate consolidated versus atelectatic segments separately by assessing the response in non-aerated zones to lung recruitment and have also looked at ratio between perfusion of non-aerated and aerated area of lungs (apparent perfusion ratio) to assess the influence of venous admixture on oxygenation response. An important observation worth this study is the change in distribution of perfusion with change in position as noticed during the preferential ARDS, which may have COVID-19 a comments which might have influenced their findings.